The present invention relates to O,S-dialkyl ((N-heterocyclyl)carbonyl)phosphoramidothioates derived from five and six membered nitrogen heterocycles, to insecticidal compositions containing the compounds, and to the use of the compounds as insecticides.
The control of insects is critical to modern agriculture and to the maintenance of public health. Although many compounds that are useful in the control of insects are known, new compounds that are more effective, are less toxic to mammals, are more compatible with the environment, are less expensive, or have other outstanding properties, are constantly sought and when found highly valued.
Many of the compounds known to be useful in the control of insects are organophosphorus compounds. Such compounds include O,S-dimethyl phosphoramidothioate (methamidophos) and O,S-dimethyl acetylphosphoramido-thioate (acephate). Certain O,S-dialkyl N,N-dialkyl-carbamoylphosphoramidothioates and their use as insecticides is disclosed in published German Patent Applications 2,718,554 and 2,805,682. The use of these known compounds as insecticides is often limited due to their toxicological and environmental properties, their lack of persistence, and their lack of activity on certain important insects.